Friday, March 18, 2011

Fukushima plumes (hypothetical!)

I should probably start off this post with a bit of a health warning, as it is based on historical data (ERA analysis), ie a series of past March conditions rather than current/forecast winds. But Ignacio Pisso, who works in the Atmospheric Geochemical Cycle Research Team of our institute (undergoing a website reorganisation, sorry) and blogs here, has produced some pretty pictures which should give some indication of the way things might tend to go.

First, some pictures of the typical 24h trajectories, these are three consecutive March data sets, 2007, 8 and 9 (actually a chunk of 20 days in each case, judging from the titles on two plots):

And also a plot of impacts, which he describes as a histogram of particles from the March 2007 hindcast, taking into account residence time:

I think the message is that the vast majority of whatever release may occur, is very likely to end up not going far and predominantly out to sea anyway. Tokyo is not marked on the map (and the coastline is rather approximate) but it is basically at the top of the first sharp inlet at around (140E, 35N) as you head south and then west round the coast, with Kamakura bit further away to the SW. Perhaps Ignacio will be able to answer further questions - this is very much more his field of research than mine!